Sufferers from depression who do not respond to existing treatments could soon benefit from a new procedure in which electrodes are inserted into the core of the brain and used to alter the patient’s mood.

Later this year, scientists at Bristol University will conduct the first trials of the so-called deep brain stimulation method on sufferers from depression. They will use hair-thin electrodes to stimulate two different parts of the brains of eight patients who suffer from an extreme form of recurrent unipolar depression – where mood only swings in one direction.

“When we turn the current on, the patients report the emptiness suddenly disappears”